Nutritional Advice El Mondo- Folic acid (also known as folate, vitamin M, vitamin B9, vitamin Bc (or folacin), pteroyl-L-glutamic acid, pteroyl-L-glutamate and pteroylmonoglutamic acid) is a water-soluble member of the B-complex family of vitamins.
- Folic acid derives its name from the Latin word folium, which means "leaf".
- Folate plays a crucial role in the one-carbon metabolism for physiological nucleic acid synthesis and cell division, regulation of gene expression, amino acid metabolism and neurotransmitter synthesis.
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Pregnancy is associated with a marked acceleration in one-carbon transfer reactions, including those required for nucleotide synthesis and thus cell division, which is the basis for the substantial increase in folate requirements during pregnancy.
Folate requirements are 5- to 10-fold higher in pregnant than in non-pregnant women. -
Low dietary intake of folic acid during pregnancy increases the risk of developing birth defects, likes delivery of a child with a neural tube defect (NTD). Birth defects occur within the first 3-4 weeks of pregnancy.
To reduce the risk of developing birth defects, experts recommend to take 400 micrograms (mcg) of folic acid per day, beginning at least a month before the pregnancy until the first 2 months of pregnancy. - It is impossible to get 400 mcg of folic acid from food.
- Dietary folic acid, or the form naturally found in foods, is actually a complex and variable mixture of folate compounds, such as polyglutamate (multiple glutamate molecules attached) conjugate compounds, reduced folates and tetrahydrofolates.
- Cooking or processing destroys folic acid.
- The recommended daily allowance is 200-300 mcg.
- The best folate sources in foods are green, leafy vegetables, sprouts, fruits, brewer’s yeast, liver and kidney.
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Signs and symptoms of folate deficiency include macrocytic anemia, fatigue, irritability, peripheral neuropathy, tendon hyper-reflexivity, restless legs syndrome, diarrhea, weight loss, insomnia, depression, dementia, cognitive disturbances and psychiatric disorders.
Elevated plasma homocysteine can also indicate a dietary or functional deficiency of folic acid. - Homocysteine metabolism is regulated by the nutritional status of folate, vitamin B12, and vitamin B6. Folate status has the strongest influence on plasma homocysteine concentration.
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At least 200 mcg folic acid per day is needed to prevent a high (> 12 μmol/L) plasma homocysteine concentration.
A high plasma homocysteine concentration is an independent risk factor for cardiovascular disease. - Folate deficiency can be treated with supplemental oral folate of 400 to 1000 mcg per day.
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The serum (or plasma) folate concentration and red blood cell (RBC) concentration of folate were the two most commonly used indicators of folate status.
Red cell folate concentration, which reflects liver folate concentration and is considered to be an indicator of long-term folate status. - Synthetic folic acid is 100% bioavailable when consumed under fasting conditions on an empty stomach.
- The bioavailability of food folate was 50% that of synthetic folic acid because synthetic folic acid (found in dietary supplements and folate-fortified foods) is free and the human body is only able to absorb “free form” folic acid.
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Monoglutamate folates (often found in dietary supplements and folate-fortified foods) are absorbed by an active energy-dependent, carrier-mediated process at physiological concentrations and by passive absorption at higher concentrations.
Absorption takes place mainly in the jejunum and is markedly influenced by pH with a maximum absorption at pH 6.3.
The polyglutamic folates (often found in diet) must be cleaved to their monoglutamate forms by a pteroylpolyglutamate hydrolase, referred to as folate deconjugase, before uptake can take place in the intestinal epithelial cells (primarily in the jejunum). - Folic acid intakes in excess of the tolerable upper intake level (UL) (1 mg/day) may mask the symptoms associated with a vitamin B12 deficiency and allow for the progression of irreversible neurological damage.
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The total body pool size is estimated between 12-28 mg or 3-4 weeks.
The liver contains about 50% of the body stores of folate. - 1 µg dietary folate equivalent (DFE) = 1 µg food folate = 0.5 µg folic acid on an empty stomach = 0.6 µg folic acid with meals or as fortified foods.
- The tolerable upper intake level (UL) for folic acid is 1 mg/day.
Scientific studies on the relationship between folic acid and disease prevention:
Review articles of randomized, placebo-controlled double-blind clinical trials (RCTs) will answer the following question:
"Is taking dietary supplements make sense?". Yes at a positive conclusion and no at a negative conclusion.
Review articles of cohort studies or case-control studies will answer the following question:
"Should I change my diet?".